Pivotal surgical clip

ABSTRACT

This invention relates to a surgical clip which may be attached to a blood vessel to block or restrict the flow of blood through the blood vessel. The clip comprises first and second elongated opposed members, pivot means located between the two opposed members which permit relative pivotal movement of the two members in a common plane, adjustable spring means urging the two opposed members to pivot about the pivot means to a closed position, and an enlongated blade member pivotally connected to the forward end of one of the two opposed members. The blade member has one elongated blade surface and the other opposed member has a second matched blade surface, between which the blood vessel is clamped. The fact that the blade member is pivotally connected to one of the opposed members permits the blade member to rotate slightly in the plane of the first and second opposed members to more evenly distribute the compressive force of the spring means across the blood vessel in the closed position. This avoids pinching of one portion of the blood vessel, and substantially reduces the possibility of injury or damage to the blood vessel. One of the blade surfaces has a channel with a uniform concave cross-section extending along a portion of its length. The wall of the clamped blood vessel bulges into the channel to securely laterally retain the clip on the blood vessel. A second embodiment of the invention has lips on opposite ends of one of the blade surfaces to maintain the blade surfaces in a predetermined spaced relationship, in the closed position.

United States Patent [191 Walsh et al.

1 1 PIVOTAL SURGICAL CLIP [75] Inventors: David Joseph Walsh,Mississauga;

Harry Sydney Kerr, Willowdale, Ontario, both of Canada [73] Assignee:Kerr Instruments Limited,

Willowdale, Ontario, Canada [22] Filed: June 29, 1972 ]2l] Appl. No.:267,554

Primary E.raminer-Lucie H. Laudenslager [5 7] ABSTRACT Thisinventionrelates to a surgical clip which may be attached to a blood vessel toblock or restrict the flow [451 Mar. 19, 1974 of blood through the bloodvessel. The clip comprises first and second elongated opposed members,pivot means located between the two opposed members which permitrelative pivotal movement of the two members in a common plane,adjustable spring means urging the two opposed members to pivot aboutthe pivot means to a closed position, and an enlongated blade memberpivotally connected to the forward end of one of the two opposedmembers. The blade member has one elongated blade surface and the otheropposed member has a second matched blade surface, between which theblood vessel is clamped. The fact that the blade member is pivotallyconnected to one of the opposed members permits the blade member torotate slightly in the plane of the first and second 0p posed members tomore evenly distribute the compressive force of the spring means acrossthe blood vessel in the closed position. This avoids pinching of oneportion of the blood vessel, and substantially reduces the possibilityof injury or damage to the blood vessel. One of the blade surfaces has achannel with a uniform concave cross-section extending along a portionof its length. The wall of the clamped blood vessel bulges into thechannel to securely laterally retain the clip on the blood vessel. Asecond embodiment of the invention has lips on opposite ends of one ofthe blade surfaces to maintain the blade surfaces in a predeter minedspaced relationship, in the closed position,

14 Claims, 4 Drawing Figures r PATENTEDHARIS 1914 I 3.797" 498 SHEET 1[1F 2 PATENTEDIAR 1 9 m4 3179Tl498 sum 2 or 2 h PIVOTAL SURGICAL CLIPBACKGROUND OF THE INVENTION tion comprising: (a) first and secondelongated opposed members each having a forward and a rear end and anoutwardly facing surface, the first opposed member having an elongatedfirst flat blade surface ad- This invention relates to a surgical clipwhichmay be 5 jacent its forward end, the first blade surface inwardlyattached to a vein or artery to block or restrict the flow of bloodthrough the vein or artery.

In the past, a variety of clips and clamps have been used to temporarilyor permanently restrict the flow of blood through blood vessels. Theseprevious clips have had the disadvantage that they are difficult toapply, particularly in the confined area in which they are normallyused, to be securely attached to the blood vessel without resulting indamage or injury to the blood vessel.

More recently, a clamp disclosed in Canadian Pat. No. 802,633 grantedDec. 31, 1968 to Harry Sidney Kerr has been used to partially overcomethis disadvantage. This clamp, which is widely used and known in theindustry as the Kerr Clip is similar to the present clip in that it hastwo elongated opposed members, pivot means locatedbetween the twoopposed members and adjustable spring means urging the two opposedmembcrs to pivot towards a clamped or closed position. Although theimprovements of the Kerr Clip have resulted in it being widely accepted,it still has several disadvantages. As the blade surfaces which contactthe blood vessel are bothlocated on the opposed members which pivotabove the pivot means, the blade surfaces of each size of clip arelocated parallel to each other only when attached to one particular sizeof blood vessel. The blade surfaces of the opposed membersdivergeslightly outward from the pivot means.

when attached to a blood vessel larger than that particular size andconverge slightly when used with a blood vessel which is smaller thanthat particular size. This has the effect of pinching or compressing oneside of the blood vessel more than the other thereby possible resultingin injury or damage to the blood vessel. This is of particularimportance when the clip is used on small fragile blood vesselsencountered in cranial surgery. In addition, if the blood vessel has onethick or hard transverse portion when compressed, the compression forceof the clip is not evenly distributed across the blood vessel. Anotherdisadvantage of the Kerr Clip is that there is a possibility of it beingdisplaced laterally from the blood vessel. This is particularly true ifa clip is attached to a blood vessel much larger than that for which itwas designed, as the blade faces of the opposed members substantiallydiverge outward from the pivot means. Another problem with the existingclip is that small clips which have been in place for a considerablelength of time are difficult to remove without causing injury or damageto the blood vessel to which they are attached. In particular, it isdifficult to engage the clip with a clip adjustment tool in order toopen the clip before removing it.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to at least partially'overcome these disadvantages byproviding a surgical clip which is relatively easy to apply to andremove froma secure position on a blood vessel with less possibility ofinjury or damage to the blood vessel.

To this end, in one of its aspects, the invention provides a surgicalclip having a clamped and an open posifacing the second opposed member;(b) pivot means between the opposed members permitting relative pivotalmovement of the members in a common plane about a central transverseaxes through the pivot means between the open and clamped positions; (c)an elongated blade member substantially centrally pivotally connected tothe forward end of the second opposed member for pivotal movementrelative to the second opposed member in the said common plane, theblade member having a second flat blade surface inwardly facing thefirst blade surface; and (d) adjustable pressure means acting on theopposed members to urge the opposed members to pivot about the pivotmeans to bring the first and second blade surfaces into a substantiallyaligned and contacting relationship.

In another of its aspects, the invention provides a surgical clip havinga clamped and an open position comprising: (a) first and secondelongated opposed members each having a forward and a rear end and anoutwardly facing surface, the first opposed member having an elongatedfirst flat blade surface adjacent its forward end, the first bladesurface inwardly facing the second opposed member; (b) pivot meansbetween the op posed members permitting relative pivotal movement of themembers in a common plane about a central transverse axes through thepivot means between the open and clamped positions; (c) an elongatedblade member substantially centrally pivotally connected to the forwardend of the second opposed member for pivotal movement relative to thesecond opposed member in the said common plane, the blade member havinga second flat blade surface inwardly facing the first blade surface,each of the first and second blade surfaces having a forward and arearward end; (d) adjustable pressure means acting on the opposedmembers to urge the opposed members to pivot about the pivot means tobring the first and second blade surfaces into a substantially alignedand contacting relationship; and (e) a pair of lips of predeterminedlength. extending inwardly from one of the blade surfaces, one of thelips being located near each of the forward and rearward'end of the saidone blade surface, the lips adapted to be in bearing contact with theother blade surface when the clamp is in the clamped position tomaintain the first and second blade surfaces in a predetermined spacedrelationship.

Further objects and advantages of the invention will appear from thefollowing description taken together with the accompanying drawings, inwhich:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of afirst embodiment of the invention, shown in the closed position;

FIG. 2 is a cross-sectional view of the embodiment shown in FIG. 1,attached to a blood vessel;

FIG. 3 is a perspective view of the embodiment shown in FIG. 1, in anopenposition;

FIG. 4 is a perspective view of a second embodiment of the invention,shown in the closed position.

DETAILED DESCRIPTION OF THE DRAWINGS Reference is first made to FIG. 1,which shows a clip having first and second opposed members 12, 14 and apivot roller 16 positioned therebetween. The first and second opposedmembers 12, 14 each has a forward end 18, 20 and a rear end 22, 24. Thefirst or, as shown lower, opposed member 12 has a first inwardly facingblade surface 26 extending from a point adjacent the forward end 18 ofthe first opposed member 12 to a point adjacent the roller 16. The firstopposed member 12 also has a first opposing face 28 extending from therear end 22 to the first blade surface 26, and as shown, the secondopposed member 14 has a similar second opposing face 30. The first andsecond opposing faces 28, 30 respectively have first and secondsemi-cylindrical transverse openings 32, 34 which cooperate to receivethe roller 16. The roller 16 has end flanges 36, 38 or other suitablemeans to prevent relative lateral movement between the first and secondopposed members 12, 14, while permitting relative pivotal movement ofthe first and second opposed members 12, 14 in a common plane about acentral transverse axis 40 through the roller 16 between the closed orclamped position shown in FIG. 1 and the open position shown in FIG. 3.

The clip 10 also has an elongated blade member 42 which is pivotallyconnected to the forward end 20 of the second opposed member 14 topermit relative pivotal movement between the blade member 42 and thesecond opposed member 14 in the same plane as the relative pivotalmovement between the first and second opposed members 12, 14. A pin andtongue joint 44 is shown between the blade member 42 and the secondopposed member 14, although other conventional joints which permit theabove pivotal motion may also be used. The blade member 42 is preferablysubstantially centrally connected to the forward end 20 of member 14,although the connection may possibly be closer to one end or the otherfor special applications. The blade member 42 has a second blade surface46 inwardly facing the first blade surface 26. The first and secondblade surfaces 26, 46 respectively have forward ends 48, 50 and rearwardends 52, 54, and are similar in size and shape, thereby permitting themto be in the aligned and contacting relationship shown in FIG. 1, in theclosed position.

The first and second opposed members l2, 14 have first and secondoutwardly facing surfaces 56, 58, which in turn have a series oflongitudinally spaced depressions 60, 62 extending forwardly from apoint adjacent the central transverse axis 40 through the roller 16. Theseries of longitudinally spaced depressions 60, 62 are matched toremovably retain one of the first and second ends 64, 66 of a C-shapedspring 68 in a selected one of the depressions in each of the outwardlyfacing surfaces 56, 58. The spring 68 continuously biases the first andsecond opposed members 12, 14 to pivot about the roller 16 from the openposition towards the closed position, and maintains a pressure betweenthe first and second blade surfaces 26, 46 in the closed position. Thepressure between the first and second blade surfaces 26, 46 in theclosed position may be increased by moving the first and second ends 64,66 of the spring 68 forward in the series of depressions 60, 62 anddecreased by moving them rearward.

The first and second outwardly facing surfaces 56, 58 of the first andsecond opposed members 12, 14 also have a pair of depressions 70,located rearwardly of the central transverse axis 40, and of a size andshape suitable to receive meeting projections, (not shown) on theforward ends of a forcep or other suitable clip adjusting tool. Thefirst and second opposed members 12, 14 may be pivoted about the roller16 to the open position shown in FIG. 3, by forcing the rear ends 22, 24of the first and second opposed members 12, 14 together with the clipadjusting too]. As may be seen, the rear portions of the first andsecond opposing faces 28, 30 are undercut to permit pivotal movement ofthe first and second opposed members 12, 14 through a greater arc, whichresults in the first and second blade surfaces 26, 46 being furtherapart when clip is in the open position with the rear portions of thefirst and second opposing faces 28, 30 in contact with each other. Thefirst and second outwardly facing surfaces 56, 58 of the first andsecond opposed members 12, 14 are also provided with a pair oftransverse grooves 72 located rearwardly of the transverse axis 40. Thetransverse grooves 72 are shown as each being interrupted in the centralportion of the surfaces 56, 58, but they could equally as well becontinuous across the surfaces. The grooves 72 are adapted to receive anoose 74 of thin flexible material, such as spring steel, encircling therear ends 22, 24 of the first and second opposed members 12, 14. Thenoose 74 is attached to a noose tightening tool 76 which may be manuallyoperated to tighten the noose. As the noose 74 is tightened, the rearends 22, 24 of the first and second opposed members 12, 14 are forcedtogether to the open position, with the rear portions of the first andsecond opposing faces 28, 30 in bearing contact with each other. i

The clip adjusting tool (not shown) with projections suitable forreceipt in depressions has the advantage that it permits the clip to besecurely held at a wide variety of angles relative to the longitudinalaxis of the tool, but has the disadvantage that after the clip has beeninstalled for a considerable period of time it is often difficult tolocate the depressions 70 with the projections on the clip adjustingtool. In this case, the noose tightening tool 76 may be advantageouslyused to open the clip by locating the noose 74 around the rear ends 22,24 of the first and second opposed 'members 12, 14, and tightening itwhich results in the noose being securely received in the grooves 72.Therefore, although either the clip adjusting tool with the projectionsor the noose tightening tool 76 may be used to pivot the first andsecond opposed members 12, 14 from the closed position to the openposition, the former is normally used when attaching the clip to a bloodvessel and the latter normally used when removing the clip.

The first and second blade surfaces 26, 46 are generally flat, but asmay be seen in FIGS. 2 and 3, the first blade surface has a centrallongitudinal channel extending between its forward and rearward ends 48,52.

This channel 78 has a uniform concave cross-section.

and the remaining portion of the flat blade surface forms a ridge 80entirely surrounding the channel 78.

Although the channel 78 is shown as being located in FIG. 4 shows asecond embodiment of the invention which may be used to restrict theflow of blood through a blood vessel such as the vena cava vein. As maybe seen, in this embodiment, the second blade surface 46 has first andsecond lip members 82, 84 respectively extending inwardly from itsforward and rearward ends 50, 54. In the closed position, spring 68urges lip members 82, 84 into bearing contact with first blade surface,thereby maintaining the first and second blade surfaces 26, 46 in aspaced relationship on the blood vessel. Although it is apparent thatthe first and second lip members 82, 84 may be formed of any desiredlength, they are normally of equal length to maintain the first andsecond blade surfaces 26, 46 in a parallel relationship in the closedposition. The selected length of the first and second lip members 82, 84is of course, determined by the size of the blood vessel to which theclip is to be attached and the amount of blood which it is desired topermit to flow through the blood vessel. This embodiment of theinvention does not normally have a channel similar to channels 78 in oneof the first and second blade surfaces 26, 46, since the clip islaterally retained on the blood vessel by the lip members 82, 84.

In use, the clip .10 is assembled by locating the roller 16 between thefirst and second opposed members 12, 14 in the first and secondsemi-cylindrical transverse openings 32, 34. The construction of theroller 16 with end flanges 36, 38 permits relative pivotal movement ofthe first and second opposed members 12, 14 substantially only in asingle common plane, while pin and tongue joint 44 similarly permitsrelative pivotal motion between the second opposed member 14 and theblade member 42 substantially only in the same common plane. The firstand second end 64, 66 of the C- shaped spring 68 are located in selectedones of the series of depressions 60, 62 in the outwardly facingsurfaces 56, 58 of the first and second opposed members l2, 14 to biasthe opposed members l2, 14 towards the closed positions and to maintaina desired constant pressure between the first and second blade surfaces26, 46 in the closed position.

In order to attach the clip to a blood vessel, the clip is engaged by asuitable clip adjusting tool (not shown), such as forceps, by insertingprojections on the end of thetool into the pair'of depressions 70 on therear ends 22, 24 of the first and second opposed members l2, 14. Thefirst and second opposed members l2, 14 are then pivoted to the openposition by forcing the first and second rear ends 22, 24 together withthe tool to bring the rear portions of thefirst and second opposingfaces 28, 30 into bearing contact with each other. The clip is thentransversely attached across a blood vessel by locating the clip withthe blood vessel centrally positioned between the forward and rearwardends of the blade surfaces and slowly releasing the rear ends 22, 24with the tool. As the tool is released, the spring 68 rotates the firstand second opposed members l2, 14 about roller 16 towards the closedposition and compresses the blood vessel between the first and secondblade surfaces 26, 46, as seen in FIG. 2. In the closed position, thepin and tongue joint 44 between the blade member 42, and the forward endof the second 0pposing member l41permits the blademember 42 to 6 pivotslightly to more evenly distribute the compression force of the spring68 on the blood vessel along the length of the blade surfaces. Theoptimum distribution of the force normally occurs when the blade member42 is pivoted relative to'the second opposed member 14 to align thefirst and second blade surfaces 26, 46 parallel to each other, andsubstantially reduces the possibility of injury or damage to the bloodvessel. The fact that blade member 42 will align itself to maintain arelatively constant pressure along its length also pcrmits a lessertotal compressive force to be applied between the blade surfaces toensure total blockage of flow through the blood vessel. When the clip isat tached to the blood vessel, a portion of the wall of the blood vesselbulges into channel 78 to ensure secure lateral receipt of the clip onthe blood vessel. The clip may be removed from the blood vessel byencircling the rear ends 22, 24 of the first and second opposed membersl2, 14 with noose 74 and tightening the noose with the noose tighteningtool into receipt in the transv verse grooves 72 to pivot the first andsecond opposed members 12, 14 about the roller 116 to the open position.

The embodiment of the invention shown in FIG. 4 is similarly attachedand removed from the blood vessel, the blood vessel being locatedbetween the first and second lip members 82,84 in the closed position.In this embodiment, the alignment of the blade surfaces in the closedposition is determined by a length of the lip members, as the lipmembers are normally in bearing contact with the opposite blade surfacein this position.

Although the disclosure describes and illustrates preferred embodimentsof the invention, it is to be understood that the scope of the inventionis not restricted to these particular embodiments.

What we claim is:

l. A surgical clip having a clamped and an open position comprising:

a. first and second elongated opposed members each having a forward anda rear end and an outwardly facing surface, the first opposed memberhaving an elongated first flat blade surface adjacent its forward end,the first blade surface inwardly facing the second opposed member;

b. pivot means between the opposed members permitting relative pivotalmovement of the members in a common plane about a central transverseaxis through the pivot means between the open and clamped positions;

0. an elongated blade member substantially centrally pivotally connectedto the forward end of the second opposed member for pivotal movementrela tive to the second opposed member in the said common plane, theblade member having a second flat blade surface inwardly facing thefirst blade surface, said second member being of lesser length than saidfirst member and said pivotally connected elongated blade member beingsubstantially coextensive with said first flat blade surface; and

d. adjustable pressure means acting on the opposed members to urge theopposed members to pivot about the pivot means to bring the first andsecond blade surfaces into a substantially aligned and contactingrelationship.

2. A surgical clip as claimed in claim 1 wherein the adjustable pressuremeans comprises a series of depressions spaced along the outwardlyfacing surfaces of the opposed members forward of the transverse axisthrough the pivot means, and a C-shaped spring having two ends, each endof the spring being removably engaged in a respective selected one ofthe depressions in one of the opposed members.

3. A surgical clip having a clamped and an open position comprising:

a. first and second elongated opposed members each having a forward anda rear end and an outwardly facing surface, the first opposed memberhaving an elongated first flat blade surface adjacent its forward end,the first blade surface inwardly facing the second opposed member;

b. pivot means between the opposed members per mitting relative pivotalmovement of the members in a common plane about a central transverseaxis through the pivot means between the open and clamped positions;

c. an elongated blade member substantially centrally pivotally connectedto the forward end of the second opposed member for pivotal movementrelative to the second opposed member in the said common plane, theblade member having a second flat blade surface inwardly facing thefirst blade surface, at least one of the blade surfaces having a centralchannel extending along a portion of its length; and

d. adjustable pressure means acting on the opposed members to urge theopposed members to pivot about the pivot means to bring the first andsecond blade surfaces into a substantially aligned and con tactingrelationship.

4. A surgical clip as claimed in claim 3 wherein said channel has auniform concave cross-section.

5. A surgical clip as claimed in claim 1, wherein the outwardly facingsurface of at least one of the opposed members has an indentationlocated rearward of the transverse axis through the pivot means adaptedto receive a matching projection on a suitable clip adjusting tool toprovide for engagement of the clip by the tool.

6. A surgical clip as claimed in claim 1, wherein the outwardly facingsurface of at least one of the opposed members has an indentationlocated rearward of the transverse axis through the pivot means adaptedto receive a matching projection on a suitable clip adjusting tool toprovide for engagement of the clip by the tool.

7. A surgical clip as claimed in claim 1, wherein the outwardly facingsurface of at least one of the opposed members has a transverse grooveextending at least partially across the said surface rearward of thetransverse axis through the pivot means, the groove being adapted toreceive a noose of thin flexible material encircling the first andsecond opposed members to engage the clip, the nose being adapted to betightened by a suitable noose tightening tool to operate the clip fromthe clamped to the open position.

8. A surgical clip as claimed in claim 1, wherein the outwardly facingsurface of at least one of the opposed members hasa transverse grooveextending at least partially across the said surface rearward of thetransverse axis through the pivot means, the groove being adapted toreceive a noose of thin flexible material encircling the first andsecond opposed members to engage the clip, the noose being adapted to betightened by a suitable noose tightening tool to operate the clip fromthe clamped to the open position.

9. A surgical clip having a clamped and an open position comprising:

a. first and second elongated opposed members each having a forward anda rear end and an outwardly facing surface, the first opposed memberhaving an elongated first flat blade surface adjacent its forward end,the first blade surface inwardly facing the second member;

b. pivot means between the opposed members permitting relative pivotalmovement of the members in a common plane about a central transverseaxis through the pivot means between the open and clamped positions;

c. an elongated blade member substantially centrally pivotally connectedto the forward end of the second opposed member for pivotal movementrelative to the second opposed member in the said common plane, theblade member having a second flat blade surface inwardly facing thefirst blade surface, each of the first and second blade surfaces havinga forward and a rearward end;

d. adjustable pressure means acting on the opposed members to urge theopposed members to pivot about the pivot means to bring the first andsecond blade surfaces into a substantially aligned and contactingrelationship; and

e. a pair of lips of predetermined length extending inwardly from one ofthe blade surfaces, one of the lips being located near each of theforward and rearward end of the said one blade surface, the lips adaptedto be in bearing contact with the other blade surface when the clamp isin the clamped position to maintain the first and second blade surfacesin a predetermined spaced relationship.

10. A surgical clip as claimed in claim 9 wherein the adjustablepressure means comprises a series of depressions spaced along theoutwardly facing surfaces of the opposed members forward of thetransverse axis through the pivot means, and a C-shaped spring havingtwo ends, each end of the spring being removably engaged in a respectiveselected one of the depressions in one of the opposed members.

11. A surgical clip as claimed in claim 1, wherein the pivot meanscomprises a roller adapted to be seated in cooperating transverseopenings in opposing faces of the opposed members, the roller havingmeans precluding relative lateral movement between the opposed members.

12. A surgical clip as claimed in claim 9, wherein the pivot meanscomprises a roller adapted to be seated in cooperating transverseopenings in opposing faces of the opposed members, the roller havingmeans precluding relative lateral movement between the opposed members.

13. A surgical clip as claimed in claim 1, wherein at least one of saidfirst and second opposed members is undercut adjacent the rear end topermit increased relative pivotal movement of the opposed members aboutthe transverse axis through the pivot means.

14. A surgical clip as claimed in claim 1, formed of stainless steel.

1. A surgical clip having a clamped and an open position comprising: a.first and second elongated opposed members each having a forward and arear end and an outwardly facing surface, the first opposed memberhaving an elongated first flat blade surface adjacent its forward end,the first blade surface inwardly facing the second opposed member; b.pivot means between the opposed members permitting relative pivotalmovement of the members in a common plane about a central transverseaxis through the pivot means between the open and clamped positions; c.an elongated blade member substantially centrally pivotally connected tothe forward end of the second opposed member for pivotal movementrelative to the second opposed member in the said common plane, theblade member having a second flat blade surface inwardly facing thefirst blade surface, said second member being of lesser length than saidfirst member and said pivotally connected elongated blade member beingsubstantially coextensive with said first flat blade surface; and d.adjustable pressure means acting on the opposed members to urge theopposed members to pivot about the pivot means to bring the first andsecond blade surfaces into a substantially aligned and contactingrelationship.
 2. A surgical clip as claimed in claim 1 wherein theadjustable pressure means comprises a series of depressions spaced alongthe outwardly facing surfaces of the opposed members forward of thetransverse axis through the pivot means, and a C-shaped spring havingtwo ends, each end of the spring being removably engaged in a respectiveselected one of the depressions in one of the opposed members.
 3. Asurgical clip having a clamped and an open position comprising: a. firstand second elongated opposed members each having a forward and a rearend and an outwardly facing surface, the first opposed member having anelongated first flat blade surface adjacent its forward end, the firstblade surface inwardly facing the second opposed member; b. pivot meansbetween the opposed members permitting relative pivotal movement of themembers in a common plane about a central transverse axis through thepivot means between the open and clamped positions; c. an elongatedblade member substantially centrally pivotally connected to the forwardend of the second opposed member for pivotal movement relative to thesecond opposed member in the said common plane, the blade member havinga second flat blade surface inwardly facing the first blade surface, atleast one of the blade surfaces having a central channel extending alonga portion of its length; and d. adjustable pressure means acting on theopposed members to urge the opposed members to pivot about the pivotmeans to bring the first and second blade surfaces into a substantiallyaligned and contacting relationship.
 4. A surgical clip as claimed inclaim 3 wherein said channel has a uniform concave cross-section.
 5. Asurgical clip as claimed in claim 1, wherein the outwardly facingsurface of at least one of the opposed members has an indentationlocated rearward of the transverse axis through the pivot means adaptedto receive a matching projection on a suitable clip adjusting tool toprovide for engagement of the clip by the tool.
 6. A surgical clip asclaimed in claim 1, wherein the outwardly facing surface of at least oneof the opposed members has an indentation located rearward of thetransverse axis through the pivot means adapted to receive a matchingprojection on a suitable clip adjusting tool to provide for engagementof the clip by the tool.
 7. A surgical clip as claimed in claim 1,wherein the outwardly facing surface of at least one of the opposedmembers has a transverse groove extending at least partially across thesaid surface rearward of the transverse axis through the pivot means,the groove being adapted to receive a noose of thin flexible materialencircling the first and second opposed members to engage the clip, thenose being adapted to be tightened by a suitable noose tightening toolto operate the clip from the clamped to the open position.
 8. A surgicalclip as claimed in claim 1, wherein the outwardly facing surface of atleast one of the opposed members has a transverse groove extending atleast partially across the said surface rearward of the transverse axisthrough the pivot means, the groove being adapted to receive a noose ofthin flexible material encircling the first and second opposed membersto engage the clip, the noose being adapted to be tightened by asuitable noose tightening tool to operate the clip from the clamped tothe open position.
 9. A surgical clip having a clamped and an openposition comprising: a. first and second elongated opposed members eachhaving a forward and a rear end and an outwardly facing surface, thefirst opposed member having an elongated first flat blade surfaceadjacent its forward end, the first blade surface inwardly facing thesecond member; b. pivot means between the opposed members permittingrelative pivotal movement of the members in a common plane about acentral transverse axis through the pivot means between the open andclamped positions; c. an elongated blade member substantially centrallypivotally connected to the forward end of the second opposed member forpivotal movement relative to the second opposed member in the saidcommon plane, the blade member having a second flat blade surfaceinwardly facing the first blade surface, each of the first and secondblade surfaces having a forward and a rearward end; d. adjustablepressure means acting on the opposed members to urge the opposed membersto pivot about the pivot means to bring the first and second bladesurfaces into a substantially aligned and contacting relationship; ande. a pair of lips of predetermined length extending inwardly from one ofthe blade surfaces, one of the lips being located near each of theforward and rearward end of the said one blade surface, the lips adaptedto be in bearing contact with the other blade surface when the clamp isin the clamped position to maintain the first and second blade surfacesin a predetermined spaced relationship.
 10. A surgical clip as claimedin claim 9 wherein the adjustable pressure means comprises a series ofdepressions spaced along the outwardly facing surfaces of the opposedmembers forward of the transverse axis through the pivot means, and aC-shaped spring having two ends, each end of the spring being removablyengaged in a respective selected one of the depressions in one of theopposed members.
 11. A surgical clip as claimed in claim 1, wherein thepivot means comprises a roller adapted to be seated in cooperatingtransverse openings in opposing faces of the opposed members, the rollerhaving means precluding relative lateral movement between the opposedmembers.
 12. A surgical clip as claimed in claim 9, wherein the pivotmeans comprises a roller adapted to be Seated in cooperating transverseopenings in opposing faces of the opposed members, the roller havingmeans precluding relative lateral movement between the opposed members.13. A surgical clip as claimed in claim 1, wherein at least one of saidfirst and second opposed members is undercut adjacent the rear end topermit increased relative pivotal movement of the opposed members aboutthe transverse axis through the pivot means.
 14. A surgical clip asclaimed in claim 1, formed of stainless steel.